I have a sat nav running IGO 8 Software, it has been working fine until the other day.
The best way I can describe the problem is that the system is not keeping its correct position on the road, as an example I am driving past roads before the system does, thus rendering any directions useless as effectively I have passed the junction or road I should be turning at.
I have reset the sat nav, I have also made sure that the "keep road position" box is selected in the menu.
My TomTom was doing the same thing a few weeks ago .. I went to the TomTom site and updated it, and that solved the delayed action issue.
Funnily enough I only updated it about 2 months prior to that.